(How) Is it possible to get all available liquid variables from a template?

[dkbast]

I have a scenario where I have multiple liquid themes which can be interchanged. Instead of a dynamic database I use a CSV file, so I have to know all the variables upfront.
Let me explain this with a simplified example:

For these three Themes:
Theme 1:
title
text
image

Theme 2:
title
text
image

Theme 3:
image
subtitle

I would like to get the output of: title, text, image, subtitle

Is there a builtin routine I have missed? What would be the best way for accomplishing this?

[harttle]

As far as I know, there's no such feature in the Liquid template language. See Shopify/liquid#685 But it's possible to achieve this by registering a custom tag/filter

[timuster]

@harttle With this now being supported in Liquid (see this comment), is there any way to make it work with LiquidJS?

[harttle]

Not now. We don't have a parsetreevisitor yet. But I'm open for this feature.

[FrankHeijden]

I am also looking for this feature, my use case is that I have to fetch an object as a variable, being able to know which variables are being referenced on that object would help greatly with only fetching what is necessary :)

[FrankHeijden]

nvm, just found out about this discussion: #528
apparently there exists a content field on Token, however it is not defined in the type:

[harttle]

@FrankHeijden I believe you came across a DelimitedToken which is a subclass of Token.

I created a PR for astexplorer fkling/astexplorer#680 , hopefully one day it'll be available on https://astexplorer.net/ website.